rdf2hdt produces invalid UTF8 values? about hdt-cpp

[KonradHoeffner]

use std::str;

fn main() {
    let hex = [0xc3,0x96,0x7a,0x67,0xc3,0xbc,0x72,0x5f,0xc3,0x96,0x7a,0x61,0x74,0x61];
    let s = str::from_utf8(&hex[0..]).unwrap();
    println!("{s}");
    let hex = [0x9d,0x96,0x7a,0x67,0xc3,0xbc,0x72,0x5f,0xc3,0x96,0x7a,0x61,0x74,0x61];
    let s = str::from_utf8(&hex[0..]).unwrap();
    println!("{s}");     
}

 Compiling hex v0.1.0 (/home/konrad/tmp/hex)
    Finished dev [unoptimized + debuginfo] target(s) in 0.10s
     Running `target/debug/hex`
Özgür_Özata
thread 'main' panicked at 'called `Result::unwrap()` on an `Err` value: Utf8Error { valid_up_to: 0, error_len: Some(1) }', src/main.rs:8:39
note: run with `RUST_BACKTRACE=1` environment variable to display a backtrace